Humans ; Mycobacterium tuberculosis/genetics* ; Microspheres ; Antitubercular Agents/pharmacology* ; Mutation ; Microbial Sensitivity Tests ; Fluoroquinolones ; Drug Resistance, Bacterial/genetics* ; Tuberculosis, Multidrug-Resistant/microbiology*

Tuberculosis (TB) is an ancient infectious disease. Before the availability of effective drug therapy, it had high morbidity and mortality. In the past 100 years, the discovery of revolutionary anti-TB drugs such as streptomycin, isoniazid, pyrazinamide, ethambutol and rifampicin, along with drug combination treatment, has greatly improved TB control globally. As anti-TB drugs were widely used, multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis emerged due to acquired genetic mutations, and this now presents a major problem for effective treatment. Genes associated with drug resistance have been identified, including katG mutations in isoniazid resistance, rpoB mutations in rifampin resistance, pncA mutations in pyrazinamide resistance, and gyrA mutations in quinolone resistance. The major mechanisms of drug resistance include loss of enzyme activity in prodrug activation, drug target alteration, overexpression of drug target, and overexpression of the efflux pump. During the disease process, Mycobacterium tuberculosis may reside in different microenvironments where it is expose to acidic pH, low oxygen, reactive oxygen species and anti-TB drugs, which can facilitate the development of non-replicating persisters and promote bacterial survival. The mechanisms of persister formation may include toxin-antitoxin (TA) modules, DNA protection and repair, protein degradation such as trans-translation, efflux, and altered metabolism. In recent years, the use of new anti-TB drugs, repurposed drugs, and their drug combinations has greatly improved treatment outcomes in patients with both drug-susceptible TB and MDR/XDR-TB. The importance of developing more effective drugs targeting persisters of Mycobacterium tuberculosis is emphasized. In addition, host-directed therapeutics using both conventional drugs and herbal medicines for more effective TB treatment should also be explored. In this article, we review historical aspects of the research on anti-TB drugs and discuss the current understanding and treatments of drug resistant and persistent tuberculosis to inform future therapeutic development.
Humans ; Pyrazinamide/therapeutic use* ; Isoniazid/therapeutic use* ; Antitubercular Agents/therapeutic use* ; Tuberculosis, Multidrug-Resistant/microbiology* ; Mycobacterium tuberculosis/genetics* ; Tuberculosis/drug therapy* ; Rifampin/therapeutic use* ; Mutation ; Drug Resistance, Multiple, Bacterial/genetics*

Humans ; Isoniazid/pharmacology* ; Mycobacterium tuberculosis/genetics* ; Rifampin/pharmacology* ; Antitubercular Agents/pharmacology* ; Mutation ; Microbial Sensitivity Tests ; Tuberculosis, Multidrug-Resistant/microbiology* ; Drug Resistance, Multiple, Bacterial/genetics* ; Bacterial Proteins/genetics*

Anti-Bacterial Agents ; chemistry ; pharmacology ; Drug Resistance, Bacterial ; drug effects ; Humans ; Mycobacterium tuberculosis ; chemistry ; drug effects ; Tuberculosis, Multidrug-Resistant ; drug therapy ; microbiology

Objective: Drug-resistant tuberculosis (TB) may be resistant to one or multiple anti-TB drugs. We used generalized estimation equations to analysis the risk factors of drug-resistant TB and provide information for the establishment of a warning model for these non-independent data. Methods: The drug susceptibility test and questionnaire survey were performed in sputum positive TB patients from 30 anti TB drug-resistance surveillance sites in Zhejiang province. The generalized estimation model was established by the GENMOD module of SAS, with resistance to 13 kinds of anti-TB drugs as dependent variables and possible influencing factors, such as age, having insurance, HBV infection status, and history of anti-TB drug intake, as independent variables. Results: In this study, the probability of drug resistance at baseline level was 20.26%. Age, insurance, whether being co-infected with HBV, and treatment history or treatment withdrawal were statistically significantly correlated with anti-TB drug resistance. The prediction equation was established according to the influence degree of the factors mentioned above on drug resistance. Conclusion: The generalized estimation equations can effectively and robustly analyze the correlated binary outcomes, and thus provide more comprehensive information for drug resistance risk factor evaluation and warning model establishment.
Antitubercular Agents/therapeutic use* ; Drug Resistance, Multiple, Bacterial ; Humans ; Models, Statistical ; Mycobacterium tuberculosis/drug effects* ; Risk Factors ; Sputum/microbiology* ; Surveys and Questionnaires ; Tuberculosis/epidemiology* ; Tuberculosis, Multidrug-Resistant

A retrospective analysis was performed in two major HIV/AIDS referral hospitals in Beijing to evaluate the prevalence of Mycobacterium tuberculosis (MTB) and non-tuberculous mycobacterial (NTM) infections in HIV-infected patients. A total of 627 patients' data were reviewed, and 102 (16.3%) patients were diagnosed with culture-confirmed mycobacterial infection, including 84 with MTB, 16 with NTM, and 2 with both MTB and NTM. The most frequent clinical complication by mycobacterial infection was pulmonary infection (48/102, 47.1%). The overall rates of multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) were 11.9% and 3.4%, respectively. This study underlines the urgent need to intensify screening for mycobacteria coinfection with HIV and to prevent the spread of drug-resistant TB among HIV-infected patients.
AIDS-Related Opportunistic Infections ; epidemiology ; microbiology ; Adult ; Beijing ; Coinfection ; Extensively Drug-Resistant Tuberculosis ; epidemiology ; microbiology ; Female ; HIV Infections ; epidemiology ; microbiology ; Hospitals, Urban ; Humans ; Male ; Mycobacterium Infections, Nontuberculous ; epidemiology ; microbiology ; Mycobacterium tuberculosis ; isolation & purification ; Nontuberculous Mycobacteria ; isolation & purification ; Prevalence ; Retrospective Studies ; Sputum ; microbiology ; Tuberculosis, Multidrug-Resistant ; epidemiology ; microbiology ; Tuberculosis, Pulmonary ; epidemiology ; microbiology

China has a double burden of diabetes mellitus and tuberculosis, and many studies have been carried out on the mutual impact of these two diseases. This paper systematically reviewed studies conducted in China covering the mutual impact of epidemics of diabetes and tuberculosis, the impact of diabetes on multi-drug resistant tuberculosis and on the tuberculosis clinical manifestation and treatment outcome, the yields of bi-directional screening, and economic evaluation for tuberculosis screening among diabetes patients.
China ; epidemiology ; Coinfection ; epidemiology ; etiology ; microbiology ; Diabetes Mellitus ; epidemiology ; etiology ; Epidemics ; Mass Screening ; economics ; Prevalence ; Tuberculosis ; epidemiology ; microbiology ; Tuberculosis, Multidrug-Resistant ; epidemiology ; microbiology

A worsening scenario of drug-resistant tuberculosis has increased the need for new treatment strategies to tackle this worldwide emergency. There is a pressing need to simplify and shorten the current 6-month treatment regimen for drug-susceptible tuberculosis. Rifamycins and fluoroquinolones, as well as several new drugs, are potential candidates under evaluation. At the same time, treatment outcomes of patients with drug-resistant tuberculosis should be improved through optimizing the use of fluoroquinolones, repurposed agents and newly developed drugs. In this context, the safety and tolerance of new therapeutic approaches must be addressed.
Animals ; Antitubercular Agents/adverse effects/*therapeutic use ; *Drug Discovery ; *Drug Repositioning ; Drug Resistance, Bacterial ; Drug Therapy, Combination ; Extensively Drug-Resistant Tuberculosis/drug therapy/microbiology ; Humans ; Lung/*drug effects/microbiology ; Mycobacterium tuberculosis/*drug effects/pathogenicity ; Treatment Outcome ; Tuberculosis, Multidrug-Resistant/diagnosis/*drug therapy/microbiology ; Tuberculosis, Pulmonary/diagnosis/*drug therapy/microbiology

The objective of this prospective study of the risks of treatment failure in patients with drug-susceptible pulmonary tuberculosis (PTB) was to provide reference data to help develop a disease control strategy. Participants were recruited in eight provinces of China from October 2008 to December 2010. A total of 1447 patients with drug-susceptible PTB and older than 15 years of age were enrolled. Demographic characteristics, bacteriological test results, and patient outcome, i.e., cure or treatment failure were recorded and compared using the chi-square or Fisher's exact tests. Multivariate logistic regression was used to identify factors associated with risk of treatment failure. Of the 1447 patients who were enrolled, 1349 patients (93.2%) were successfully treated and 98 (6.8%) failed treatment. Failure was significantly associated with age 365 years [odds ratio (OR)=2.522, 95% confidence interval (CI): (1.097-5.801)], retreatment [OR=2.365, 95% CI: (1.276-4.381)], missed medicine [OR=1.836, 95% CI: (1.020-3.306)], treatment not observed [OR=1.879 95% CI: (1.105-3.195)], and positive culture result after the first [OR=1.971, 95% CI: (1.080-3.597)] and second month [OR=4.659, 95% CI: (2.590-8.382)]. The risk factors associated with treatment failure were age 365 years, retreatment, missed medication, treatment not observed, and positive culture at the end of month 1 or month 2. These risk factors should be monitored during treatment and interventions carried out to reduce or prevent treatment failure and optimize treatment success.
Adolescent ; Adult ; Aged ; Antitubercular Agents ; therapeutic use ; China ; epidemiology ; Female ; Humans ; Male ; Middle Aged ; Mycobacterium tuberculosis ; drug effects ; physiology ; Prospective Studies ; Retreatment ; Risk Factors ; Treatment Failure ; Tuberculosis, Multidrug-Resistant ; drug therapy ; epidemiology ; microbiology ; Tuberculosis, Pulmonary ; drug therapy ; epidemiology ; microbiology ; Young Adult

BACKGROUND/AIMS: We evaluated the trend in the rates of drug-resistant tuberculosis (TB) over time, as well as the difference in the drug-resistance pattern between pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) at a private referral center in South Korea. METHODS: All patients with culture-confirmed TB from 2006 to 2013 were included. RESULTS: In total, 1,745 patients were included: 1,431 (82.0%) were new cases, and 314 (18.0%) were cases treated previously; 1,610 (92.3%) were diagnosed with PTB, and 135 (7.7%) were diagnosed with EPTB. Multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB were detected in 5.8% and 2.0% of new cases and in 20.1% and 8.6% of previously treated cases, respectively. The MDR TB rate during the study period decreased remarkably, whereas the MDR and XDR TB rates decreased significantly in previously treated cases. No difference in the drug-resistance rate was detected between PTB and EPTB. CONCLUSIONS: The TB drug-resistance rate, particularly that of MDR TB, remained high at a private referral hospital, and the drug-resistance rate did not decrease significantly from 2006 to 2013. This finding underscores the need for a national survey regarding the prevalence of drug-resistant TB to obtain the most accurate and current drug-resistance status in South Korea, including the private sector.
Adult ; Aged ; Antitubercular Agents/*therapeutic use ; *Drug Resistance, Multiple, Bacterial ; Extensively Drug-Resistant Tuberculosis/drug therapy/microbiology ; Female ; Hospitals, Private ; Humans ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Mycobacterium tuberculosis/*drug effects/isolation & purification ; Prevalence ; Republic of Korea/epidemiology ; Retrospective Studies ; *Tertiary Care Centers ; Time Factors ; Treatment Outcome ; Tuberculosis, Multidrug-Resistant/diagnosis/*drug therapy/epidemiology/*microbiology ; Tuberculosis, Pulmonary/diagnosis/*drug therapy/epidemiology/*microbiology